From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4E2C83F9F9; Mon, 8 Jul 2024 09:36:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720431398; cv=none; b=jGE8Gw/EfdITj11g2ZlS6mgAP+lBrhnJCUrJZn493gj5eR4qJpeBZaNe+U3NxrbA7+U7Um9W2CPMx2YJVxoiHVCnqePKMHknKQAC7OwMOMh4568pWcPx5h+hsjDErTAAC8mJmdqRo/9FsllKH+EtnCJ88ODd9DF9Kz7/qIdJnuM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720431398; c=relaxed/simple; bh=Xiw5vB0052Gl+ZR1KcxMzIPi0K4sjO2ctTIPiltoYm4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=EyXlfywUWzohuYRbpDjo56TGSS0uMjE4pAM6jBUkwGpqNtJPLT7axR2bFP9n6qqKz6K5A4mkM3Ycwh+uqqcc/tRiqNRuLF+uOJ4NcmEcJjA05Gtwe/ML1B/OmWq8fMcnPAfjHOwF8/qTfFANk2/fynpEjIwg3Ly7t55WShzJSDA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nD71evyH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nD71evyH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B69F8C116B1; Mon, 8 Jul 2024 09:36:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720431397; bh=Xiw5vB0052Gl+ZR1KcxMzIPi0K4sjO2ctTIPiltoYm4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nD71evyHcTYyqnKhYOjZ2rvE1kNbKK4fnjwv9H9/q4Gl4v77btpI0VPjF5Axl9uxQ zf6kWsNDkwMq3R/ag7pDQ3aQnkKN6QAosSO/GatB5xms1cHhBP9NfbM4sFW7DiYnPx irzKjsb2C6DVkaGGQ0j3WkLeMJE27TFQOOkFhxoMnck7JKfbarrXcEy3q/y/MHPiBQ 0VFEB5KFEKtkNZLvbKTAgqYbo2rfyPNP5kH1Le9VrjSKh80LCf8+lXwpNgyTZke2Rc 5//FidY4WjFL3DuCymBmccvJMLfqgvNBdG4jPHKE1cIegjJ9v888E39LlJlN6TnBUA 52ibJZjxn41bg== Date: Mon, 8 Jul 2024 10:36:31 +0100 From: Will Deacon To: Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= Cc: Jean-Philippe Brucker , lpieralisi@kernel.org, robh@kernel.org, bhelgaas@google.com, krzk+dt@kernel.org, conor+dt@kernel.org, liviu.dudau@arm.com, sudeep.holla@arm.com, joro@8bytes.org, robin.murphy@arm.com, nicolinc@nvidia.com, ketanp@nvidia.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, devicetree@vger.kernel.org Subject: Re: [PATCH v2 1/3] dt-bindings: PCI: generic: Add ats-supported property Message-ID: <20240708093630.GA11302@willie-the-truck> References: <20240607105415.2501934-2-jean-philippe@linaro.org> <20240607105415.2501934-3-jean-philippe@linaro.org> <20240706032431.GH1195499@rocinante> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240706032431.GH1195499@rocinante> User-Agent: Mutt/1.10.1 (2018-07-13) Hi Krzysztof, On Sat, Jul 06, 2024 at 12:24:31PM +0900, Krzysztof Wilczyński wrote: > > Add a way for firmware to tell the OS that ATS is supported by the PCI > > root complex. An endpoint with ATS enabled may send Translation Requests > > and Translated Memory Requests, which look just like Normal Memory > > Requests with a non-zero AT field. So a root controller that ignores the > > AT field may simply forward the request to the IOMMU as a Normal Memory > > Request, which could end badly. In any case, the endpoint will be > > unusable. > > > > The ats-supported property allows the OS to only enable ATS in endpoints > > if the root controller can handle ATS requests. Only add the property to > > pcie-host-ecam-generic for the moment. For non-generic root controllers, > > availability of ATS can be inferred from the compatible string. > > Applied to dt-bindings, thank you! > > [1/1] dt-bindings: PCI: generic: Add ats-supported property > https://git.kernel.org/pci/pci/c/631b2e7318d45 FWIW: I already picked this up in the IOMMU tree last week. If you need it to avoid a conflict, then you can pull from the pci/ats branch: https://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux.git/commit/?h=pci/ats&id=40929e8e5449a18bc98baf7a907dd6674bd60049 Cheers, Will